Piston and liner



- Ot. 2l`, 1941. ,n.BusHBY 2,250,001

' PIsToN AND LINER l Filed April 27, 1940 I. 1 I ff: J2

Patented Oct. 21, 1941 i f `.fu-151.117so STATES PATENT o Price. Y 2,260,091,

PISTON AND .LINE-R `VDavia ius'hby, Regina', Saskatchewan; canada., assignor to The Vacuum ISH-'Pressure'r Compa-ny Limited, `Regina, Saskatchewan, 'Canada npmieauonapfnai,194112!Seriana-:s325056 40mm-s. .(01. 309-12) Myinvention: relates to `improvements '.inpistons, theprincipal object .of .theinvention being vto provide a device of the character herewithin :described .consisting -Vof the combination with a specially machined Vpiston of a removable liner therefor, which when worn may be Vremoved and anew liner substituted therefor. Y

-Y .A .f-urtherobject of .my invention lis to vprovide vla vdevicerof .the character herewithin described which embodies vthe combination with a specially machined piston .ofan adjustable split .liner and shim-*rings which may be transferred .from a special ring groove at theupper end .of the liner 'toa-shim .groove at the lower endof the liner as :the liner itself becomes worn.

v:With :theiabove more vimportant objects in View `andsuchother vminor objects as may appear .as the :specification proceeds, my invention consists :essentially .in :the arrangement and construction .of .parts all as hereinafter 'more .particularly described, reference beinghad to the accompanying drawing, in which: Figure 1 is aside elevation `partly .in section of my special pistonandiillustrating the replaceable liner. therefor.

Figure '2.is a sectional elevation along .theline v2.-'--2 :of Figure 1. f '..Figure Sais .a .side elevation partly in. section .illustrating my'piston and' speical adjustable split linerrin .the unworn position. f'

...Figure Llis a fragmentary sectional elevation illustrating the embodiment of Figure 3 in worn 5oz-.adjusted position.

In the drawing like characters of .reference indicate 'corresponding parts in the different figures.

The piston I of the embodiment of my invention illustrated in the accompanying Figures 1 and 2, is provided around the upper end of the wall 2 thereof with conventional annular ring grooves 3, for compression and oil rings collectively enumerated 4. The outer surface 5 of the piston wall is however tapered by machining around its circumference, inwardly toward the base from a plane medially of its length and transverse to the axis of the piston, this plane being preferably somewhat above the intermediate transverse plane of the piston.

Designed to engage with the tapered surface 5 of my piston is a removable and replaceable liner 6 having an outer cylindrical surface 'I and an inner surface 8 tapered complementarily to the surface 5 of the piston.

The liner 6 is retained in position upon the piston by means of the pins 9, which extend .throughiirillingsadjacent the skirt or lower :end :I I iofithe piston-and project into aligned .recesses -I'2:drilled partially Lthrough the thick-.ness of the lliner from the; ein-ner surface thereof, ithese @pins being `provided with pointedinner ends fl3, .which project upon the .interior 'I4 of :the piston .wall and 7are' capable .ofzbeing .engaged by .complementarily shaped .conical apertures in .a split retaining ring 115.

From ith'e Vforegoing .it Iwill clearly vbe perceived :thatiI have .provided simplified means by which my linerv maybe preserved vvery yrigidly in .place during rits period of service.

Proceeding .now .to fdescrib'e my piston .and .adjustable liner fas,'illustrated in the laccompanying Figures '3 .and-.4,it will .benoted upon reference wto theseillustrations that :my piston .I6 bears a .'closeresemblance tothe piston .I .insofar .as :both

are fprovided with vconventional compression and oil rings positioned .inannular ring grooves adjacentthe .upper tends thereof, the .piston .I6 being also tapered by machining uniformly. around its :circumference and inwardly towards the base as zal; 131.

this.embodiment of :my piston, however, 'I provide..annularggrooves I8 and I9, the former Aof which machined., approximately at the. trans- -verse planer where 'the .tapered surface vI'I :commences-:whilegthe .latter is machined around the skirt or adjacent-the lower edge 2190i my piston.

The adjustable .Liner 2| employed `with this iemboilimentfof myginvention is split diagonally fas.irat,z22.',the:split edges, however, being at right angles-to the `upper .and ylower circumferential 'edges 23 tof athezflinerras at 24, although the particular form-of division illustrated in the accompanying Figure 3 is not of course essential.

The inner surface of my liner 2l is set at the upper edge as at 25 to engage with the lower of a pair of retaining rings 26 positioned in the groove I8, a similar pair of rings 21 being positioned in the groove I9.

The lower edge 28 of my split adjustable liner bears against the uppermost of the rings 21 and between this pair of rings and the pair of rings 26, may be interposed shim rings 29, by means of which my adjustable liner I'I may be maintained at progressively advanced positions upon the piston according to the amount of wear upon the surface 2| thereof.

In Figure 3 I have shown my liner in the position it would occupy when new or unworn and in this illustration it will be seen that the shim rings 29 are interposed between the retaining rings 26.

When slightly worn, however, the liner may accompanying Figures 3 and 4, I would point out that the retaining rings 21 may themselves be,y

maintained in place if desired, by means of the stepped lock ring 35 of the configuration clearly illustrated and which in itsturn is maintained in position by cotter pins 3|, which "extend with an annular groove at approximately the plane where said taper commences, said liner being split and having a cylindrical outer surface and an inner surface tapered complementarily to the tapered portion of said piston surface, an

annular groove encompassing said piston adjacent the lower edge thereof, the upper and lower edges of said liner when unworn projecting partially over said first and last mentioned grooves respectively, retaining rings in said grooves and Van annular transferable shim or shims designed to be positioned in said rst mentioned groove p between the retaining ring therein and the upper Y, edge of said liner, said shim or shims being t1 ans- Vferable from said rst mentioned groove to said -last mentioned groove following the temporary removal of `said liner for this purpose as Wear through apertures in the skirt of the piston4 or adjacent the lower edge thereof. It will be noted that in the several figures illustrating the two embodiments of 'my invention above described, Ihave shown a particular `piston pin mounting arrangement collectively enumerated SZ, via which the connectingv rod V33 is secured. The same forms no part of the present specification, however, the same being more fully illustrated. described and defined in my patent application Serial Number 314,004.

What I claim as my invention is:

l. In combination a piston and removable liner therefor, annular ring grooves in said piston wall adjacent the upper end thereof, said piston being tapered inwardly towards the base from a plane medially of its length and transverse to its axis, said liner, surrounding .the tapered portion of said piston in the manner of a sleeve and being tapered complementarilysupon the inner surface thereof, a plurality .of apertures extending through said piston onV a plane transverse to the axis thereof, adjacent the lower edge of said piston, and pins projecting through said apertures for retainin said liner'upon said piston.

2. The device as deiinedin claim V1 in which said pins are designed to extend into recesses formed extending partially through the thickness of said liner vfrom the inner surface thereof, said recesses being aligned with said apertures, and asplit ring provided with a plurality of recesses therein extending around the inner surface ofsaid pistonthe projecting ends of said pins being' receivable into said recesses.

takes place upon the cylindrical outer surface of said liner.

4. A piston and an adjustable liner positioned thereon, said piston being lcircumferentially tapered inwardly towards the base thereof from a plane normal to the piston axis and medially of the length thereof, said piston being vprovided with an annular groove at approximately the plane where said taper commences, said liner being split and having Va cylindrical outer surface and an inner surface tapered complementarily to the tapered portion of said piston surface, an annular groove .encompassing said piston adjacent the lower edge thereof, the upper andlower edges of said liner when unworn'projecting partially over said first and last mentioned grooves respectively, the upper edge of said liner being stepped outwardly from the rear tapered surface thereof, a pair of retaining rings ineachrof said first and last mentioned grooves, an annular transferable shim or shims designed to be received in said rst mentioned groove and between said retaining rings when said liner is unworn, said shims being transferable upon the temporary removal of said liner for this purpose, ,to said last mentioned groove and between the retaining rings therein as wear takesrplace upon .the cylindrical outer surface of said liner, one'edgeof the lowermost retaining rings in said first mentioned groove being bearable against the stepped rupper' edge of said liner, said stepped edge providing a projecting flange acting to retain said shims in place when in saidirst mentioned groove and a stepped lock ring to maintain the retaining rings within said last mentioned groove in place and also the shim or shims when transferred thereinto. Y, Y Y 1 DAVID BUSHBY. i 

